The "Hurricane Resistant Foam-Concrete Structural Composite" is the work of inventor P. Kelly Moore of Jupiter, Fla., and received U.S. Patent No. 6,185,891 on Feb. 13, 2001. The invention is an alternative method to traditional framed wall and trussed roof building construction—and it's also a derivative of concrete home-building systems that use insulating concrete forms.
Blocks of environmentally sensitive foamed styrene, made rigid by steel C-channels inserted at the edges, serve as the underlying structure of both the wall and roof members. The foam is designed with channels for accepting steel-reinforcing rods centered on 4-foot spacings. After erecting the foam blocks, builders pour special concrete slurry into the channels.
The aqueous cement slurry includes EVAC and polymer fibers. The hardened cement slurry is then thinly applied to the foam panel surfaces in several coats to the desired thickness, typically half an inch. The cement slurry combines with the reinforcing rods to create a rigid skeletal structure to which the foam panels are anchored. The roof construction uses the same slurry-reinforcing rod design but also incorporates a centrally located reinforcing member that connects to the vertical reinforcing rods to support the designed roof loads.
According to the patent, the foam panel interface allows the structure to resist wind velocities of 155 to 310 mph. Granted, this is quite a range, but according to Moore, the system easily withstands winds of 190 mph. Also, the invention more than meets the "Large Missile Impact Test" standards.
Along with their severe weather duty, these structures enhance thermal insulation properties. According to Moore, the composite material has insulation properties of at least R-40. The material also complies with ASTM standards for flame ratings and smoke production. The other R-40 Homes partner, Barbara G. Goransson, adds that this system makes it possible to build a value-added home for $55 per square foot, compared with the typical $95 per square foot to which builders in many areas may be accustomed.